Study on Wearable Gaze-Based Communication System for Patients with Amyotrophic Lateral Sclerosis (ALS)

This study centers its attention on communication among ALS patients with severe symptoms, which is essential to daily life and the part that remains a difficulty. Also, communication is important to promote social participation and ability of independence. To promote social participation and improve the ability of independence without the restrictions for patients, the purpose of this study is to develop a wearable interface that enables communication based on the patient's voluntary intent, without temporal, spatial, or physical restrictions, and to confirm the feasibility of intention transmission using a new text entry algorithm. The developed interface utilized a see-through type head-mounted display (HMD) with a gaze estimation sensor to enable patients themselves to transition between cyberspace and physical space and to communicate by the system without restrictions of posture or usage environment during daily life activities. The letter selection is triggered by a change in the direction of the gaze trajectory. This method of letter selection reduces the burden on the user by avoiding the effects of dwell time and other factors associated with gazing input. The key layout for text input UI considers the characteristics of human eye movements, to minimize key selection errors and allows for quick viewpoint movement. To confirm the feasibility of the basic performance, we conducted the experiment with three able-bodied participants using the developed system and a conventional system as a comparison system, respectively. As a result, the developed system was able to input sentences in the same amount of time as the conventional system. The results show that the developed system has the basic performance of a communication interface with a new character input method based on eye movement functions. Therefore, we confirmed the feasibility of transmitting intention using a new text entry algorithm to enable communication without the restrictions.